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Re: [PATCH] PR80101: Fix ICE in store_data_bypass_p
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: Segher Boessenkool <segher at kernel dot crashing dot org>
- Cc: gcc-patches at gcc dot gnu dot org, Kelvin Nilsen <kdnilsen at linux dot vnet dot ibm dot com>
- Date: Tue, 18 Apr 2017 22:01:02 +0200
- Subject: Re: [PATCH] PR80101: Fix ICE in store_data_bypass_p
- Authentication-results: sourceware.org; auth=none
- References: <ceb839ae-0101-11d2-d5ce-b402c7dcfe51@linux.vnet.ibm.com> <2042575.QfhRid7aWy@polaris> <20170407091940.GV4402@gate.crashing.org>
[Sorry for the long delay]
> Why is it nonsense? The predicate gives the answer to the question
> "given these insns A and B, does A feed data that B stores in memory".
> That is a perfectly valid question to ask of any two insns.
I disagree, for example it's nonsensical to send it a blockage insn.
> There are workarounds to this problem as well: mips_store_data_bypass_p,
> added in 2006. mep_store_data_bypass_p, added in 2009 (the port has
> been removed since then, of course).
I see, no strong opinion then, but individual back-ends should be preferably
fixed if this is easily doable instead of changing the middle-end, which may
affect the other ~50 back-ends.
--
Eric Botcazou